A power generation system having a power generation equipment such as a solar panel and the like is provided with a grid-connected inverter apparatus that converts a direct current (DC) from the power generation equipment into an alternating current (AC) and supplies power to loads on a premise by interconnecting with the grid or conducts reverse power flow of excess power to the grid. Such a grid-connected inverter apparatus is also called as a power conditioner and provided with an inverter for converting the DC from the power generation equipment into the AC and a grid interconnection switch for connecting the inverter to the grid (for example, see Patent Document 1).
The grid interconnection switch is usually constituted by using a relay switch and, upon occurrence of abnormalities of a grid voltage due to a power failure and the like, upon occurrence of a fault in the grid-connected inverter apparatus itself, or upon stopping operation of a driving operation by a user, switched off by a control unit. Thereby, the inverter is disconnected from the grid, such that the safety of the power generation system and the grid is ensured.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-27764